<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="app">
    <h3>礼物清单</h3>
    <table>
      <tr>
        <th>名字</th>
        <th>数量</th>
      </tr>
      <tr v-for="(item, index) in list " :key="item.id">
        <td>{{item.name}}</td>
        <td>{{item.num}}</td>
      </tr>
    </table>
    <p>礼物总数: {{totalCount}}个</p> <!-- 注意这里是不能加括号的 不是函数 是个属性 -->
  </div>
  <script src="../vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        list: [
          { id: 1, name: '篮球', num: 1 },
          { id: 2, name: '玩具', num: 2 },
          { id: 3, name: '铅笔', num: 5 }
        ]
      },
      methods: {

      },
      computed: {
        totalCount() {
          //可以直接通过this去访问
          // reduce里面的0是起始值会给到sum  sum作为一个临时变量
          let total = this.list.reduce((sum, item) => sum += item.num, 0)
          return total
        }
      }
    })
  </script>

</body>

</html>